Supplementary materials

Table S1: Complete list of all considered EPB events during the Swarm counter-rotation period. In the middle part the detection of plasma depletions either by Swarm A, Swarm B or by both is marked for every degree of ApexLat. In some places “MST” mark the appearance of Medium-Scale Traveling Ionospheric Disturbances rather than plasma bubbles. (Access here)

Table S2: Evaluation of bubble scale-length based on simultaneous observations of plasma depletions on the same fluxtubes by either one or both Swarm spacecraft. The columns contain results obtained from fluxtubes labelled by their apex latitude. The rows in the upper half list either the numbers of single-satellite EPB detections by Swarm A or B, below the double detections and the Sum at the various fluxtubes from the considered 28 prime events. In the lower part the values of parameters for calculating scale-length are listed (for definition see Eq. (4) in parent paper). The bottom row presents the estimates for the field-aligned bubble lengths. All numbers in parenthesis are derived from the full set of 46 EPB events allowing for longitudinal separations up to 1.5° ∆MLon. (Access here)

Figure S1: Increase of available events for the scale-length study with a growing range of allowed difference in magnetic longitude, ∆MLon, between Swarm A and B EPB detections.

Figure S2: (46 frames). For all the considered events the quasi-simultaneous observations of equatorial plasma bubbles by the three Swarm spacecraft are shown. The listed times and locations of the spacecraft are valid for + or −15° ApexLat, depending on the hemisphere. (Access here)

© C. Xiong and H. Lüh, Published by EDP Sciences 2023